When making music, practicing, learning new pieces it is not possible to avoid making mistakes: wrong notes, wrong rhythm, bad preparation, wrong movements, bad concentration, etc. But it is not about trying not to make mistakes, instead much more to learn how to deal with mistakes that are happening during lessons, while practicing at home and performing. Mistakes are part of the learning process and an opportunity for improvement and learning. Mistakes can point out important things for us, which need or could improve. But the most important thing to know is, that mistakes are not failures. Making a mistake is not defining your capabilities, your motivation or you as a person. If you become aware of a mistake during your practicing or lesson, first stay calm, own the mistake and start to analyze it. Try to find out honestly and in an objective way what you did wrong. What was I trying to do? What went wrong? At which point did I make a wrong movement? Did the mistake happen consciously or unconsciously? Try to understand why this mistake happened. Try to figure out the challenge with better and the right questions. And then start to correct. What did I just learn for not repeating this mistake? Prepare, ask, try again for not repeating the same mistake again (which can be a wrong note, rhythm, not a nice sound, tempo too fast, …). It can be also very helpful to write down what you have discovered and learned.
Accept that mistakes are happening all the time to us human beings and that this is totally normal. Use them as great source for learning. The same way how Thomas Edison did, who still didn’t give up after thousands of trials to find a way how to make a light bulb glow and who said: “Never give up! Our greatest weakness lies in giving up. The most certain way to succeed is always try just one more time.”
Wishing you a lot of joy making music!